← The Power of Habit Why We Do What We Do in Life and Business
The Power of Habit Chapter 1. The Habit Loop: How Habits Work
Author: Charles Duhigg Publisher: New York, NY: Penguin Random House. Publish Date: 2012 Review Date: 2023-12-1 Status:💥
Annotations
27
In the early 1990s, the MIT researchers began wondering if the basal ganglia might be integral to habits as well. They noticed that animals with injured basal ganglia suddenly developed problems with tasks such as learning how to run through mazes or remembering how to open food containers.1.15 They decided to experiment by employing new micro-technologies that allowed them to observe, in minute detail, what was occurring within the heads of rats as they performed dozens of routines. In surgery, each rat had what looked like a small joystick and dozens of tiny wires inserted into its skull. Afterward, the animal was placed into a T-shaped maze with chocolate at one end.
314
1.15 to open food containers I am indebted to the following sources for expanding my understanding of the work at the MIT labs, the basal ganglia, and its role in habits and memory: F. Gregory Ashby and John M. Ennis, “The Role of the Basal Ganglia in Category Learning,” Psychology of Learning and Motivation 46 (2006): 1–36; F. G. Ashby, B. O. Turner, and J. C. Horvitz, “Cortical and Basal Ganglia Contributions to Habit Learning and Automaticity,” Trends in Cognitive Sciences 14 (2010): 208–15; C. Da Cunha and M. G. Packard, “Preface: Special Issue on the Role of the Basal Ganglia in Learning and Memory,” Behavioural Brain Research 199 (2009): 1–2; C. Da Cunha et al., “Learning Processing in the Basal Ganglia: A Mosaic of Broken Mirrors,” Behavioural Brain Research 199 (2009): 157–70; M. Desmurget and R. S. Turner, “Motor Sequences and the Basal Ganglia: Kinematics, Not Habits,” Journal of Neuroscience 30 (2010): 7685–90; J. J. Ebbers and N. M. Wijnberg, “Organizational Memory: From Expectations Memory to Procedural Memory,” British Journal of Management 20 (2009): 478–90; J. A. Grahn, J. A. Parkinson, and A. M. Owen, “The Role of the Basal Ganglia in Learning and Memory: Neuropsychological Studies,” Behavioural Brain Research 199 (2009): 53–60; Ann M. Graybiel, “The Basal Ganglia: Learning New Tricks and Loving It,” Current Opinion in Neurobiology 15 (2005): 638–44; Ann M. Graybiel, “The Basal Ganglia and Chunking of Action Repertoires,” Neurobiology of Learning and Memory 70, nos. 1–2 (1998): 119–36; F. Gregory Ashby and V. Valentin, “Multiple Systems of Perceptual Category Learning: Theory and Cognitive Tests,” in Handbook of Categorization in Cognitive Science, ed. Henri Cohen and Claire Lefebvre (Oxford: Elsevier Science, 2005); S. N Haber and M. Johnson Gdowski, “The Basal Ganglia,” in The Human Nervous System, 2nd ed., ed. George Paxinos and Jürgen K. Mai (San Diego: Academic Press, 2004), 676–738; T. D. Barnes et al., “Activity of Striatal Neurons Reflects Dynamic Encoding and Recoding of Procedural Memories,” Nature 437 (2005): 1158–61; M. Laubach, “Who’s on First? What’s on Second? The Time Course of Learning in Corticostriatal Systems,” Trends in Neurosciences 28 (2005): 509–11; E. K. Miller and T. J. Buschman, “Bootstrapping Your Brain: How Interactions Between the Frontal Cortex and Basal Ganglia May Produce Organized Actions and Lofty Thoughts,” in Neurobiology of Learning and Memory, 2nd ed., ed. Raymond P. Kesner and Joe L. Martinez (Burlington, Vt.: Academic Press, 2007), 339–54; M. G. Packard, “Role of Basal Ganglia in Habit Learning and Memory: Rats, Monkeys, and Humans,” in Handbook of Behavioral Neuroscience, ed. Heinz Steiner and Kuei Y. Tseng, 561–69; D. P. Salmon and N. Butters, “Neurobiology of Skill and Habit Learning,” Current Opinion in Neurobiology 5 (1995): 184–90; D. Shohamy et al., “Role of the Basal Ganglia in Category Learning: How Do Patients with Parkinson’s Disease Learn?” Behavioral Neuroscience 118 (2004): 676–86; M. T. Ullman, “Is Broca’s Area Part of a Basal Ganglia Thalamocortical Circuit?” Cortex 42 (2006): 480–85; N. M. White, “Mnemonic Functions of the Basal Ganglia,” Current Opinion in Neurobiology 7 (1997): 164–69.
27
The maze was structured so that each rat was positioned behind a partition that opened when a loud click sounded.1.16 Initially, when a rat heard the click and saw the partition disappear, it would usually wander up and down the center aisle, sniffing in corners and scratching at walls. It appeared to smell the chocolate, but couldn’t figure out how to find it. When it reached the top of the T, it often turned to the right, away from the chocolate, and then wandered left, sometimes pausing for no obvious reason. Eventually, most animals discovered the reward. But there was no discernible pattern in their meanderings. It seemed as if each rat was taking a leisurely, unthinking stroll.
315
1.16 The maze was structured Ann M. Graybiel, “Overview at Habits, Rituals, and the Evaluative Brain,” Annual Review of Neuroscience 31 (2008): 359–87; T. D. Barnes et al., “Activity of Striatal Neurons Reflects Dynamic Encoding and Recoding of Procedural Memories,” Nature 437 (2005): 1158–61; Ann M. Graybiel, “Network-Level Neuroplasticity in Cortico-Basal Ganglia Pathways,” Parkinsonism and Related Disorders 10 (2004): 293–96; N. Fujii and Ann M. Graybiel, “Time-Varying Covariance of Neural Activities Recorded in Striatum and Frontal Cortex as Monkeys Perform Sequential-Saccade Tasks,” Proceedings of the National Academy of Sciences 102 (2005): 9032–37.
27
The probes in the rats’ heads, however, told a different story. While each animal wandered through the maze, its brain—and in particular, its basal ganglia—worked furiously. Each time a rat sniffed the air or scratched a wall, its brain exploded with activity, as if analyzing each new scent, sight, and sound. The rat was processing information the entire time it meandered.
28
The scientists repeated their experiment, again and again, watching how each rat’s brain activity changed as it moved through the same route hundreds of times. A series of shifts slowly emerged. The rats stopped sniffing corners and making wrong turns. Instead, they zipped through the maze faster and faster. And within their brains, something unexpected occurred: As each rat learned how to navigate the maze, its mental activity decreased. As the route became more and more automatic, each rat started thinking less and less.
28
It was as if the first few times a rat explored the maze, its brain had to work at full power to make sense of all the new information. But after a few days of running the same route, the rat didn’t need to scratch the walls or smell the air anymore, and so the brain activity associated with scratching and smelling ceased. It didn’t need to choose which direction to turn, and so decision-making centers of the brain went quiet.
Note: Task positive centers
28
All it had to do was recall the quickest path to the chocolate. Within a week, even the brain structures related to memory had quieted. The rat had internalized how to sprint through the maze to such a degree that it hardly needed to think at all.
28
But that internalization—run straight, hang a left, eat the chocolate—relied upon the basal ganglia, the brain probes indicated. This tiny, ancient neurological structure seemed to take over as the rat ran faster and faster and its brain worked less and less. The basal ganglia was central to recalling patterns and acting on them. The basal ganglia, in other words, stored habits even while the rest of the brain went to sleep.
28
To see this capacity in action, consider this graph, which shows activity within a rat’s skull as it encounters the maze for the first time.1.17 Initially, the brain is working hard the entire time:
315
1.17 To see this capacity in action The graphs in this chapter have been simplified to exhibit salient aspects. However, a full description of these studies can be found among Dr. Graybiel’s papers and lectures.
28
After a week, once the route is familiar and the scurrying has become a habit, the rat’s brain settles down as it runs through the maze:
29
This process—in which the brain converts a sequence of actions into an automatic routine—is known as “chunking,” and it’s at the root of how habits form.1.18 There are dozens—if not hundreds—of behavioral chunks that we rely on every day. Some are simple: You automatically put toothpaste on your toothbrush before sticking it in your mouth. Some, such as getting dressed or making the kids’ lunch, are a little more complex.
315
1.18 root of how habits form Ann M. Graybiel, “The Basal Ganglia and Chunking of Action Repertoires,” Neurobiology of Learning and Memory 70 (1998): 119–36.
29
Others are so complicated that it’s remarkable a small bit of tissue that evolved millions of years ago can turn them into habits at all. Take the act of backing your car out of the driveway. When you first learned to drive, the driveway required a major dose of concentration,
29
Nowadays, however, you do all of that every time you pull onto the street with hardly any thought. The routine occurs by habit.
29
Millions of people perform this intricate ballet every morning, unthinkingly, because as soon as we pull out the car keys, our basal ganglia kicks in, identifying the habit we’ve stored in our brains related to backing an automobile into the street. Once that habit starts unfolding, our gray matter is free to quiet itself or chase other thoughts, which is why we have enough mental capacity to realize that Jimmy forgot his lunchbox inside.
30
Habits, scientists say, emerge because the brain is constantly looking for ways to save effort. Left to its own devices, the brain will try to make almost any routine into a habit, because habits allow our minds to ramp down more often. This effort-saving instinct is a huge advantage. An efficient brain requires less room, which makes for a smaller head, which makes childbirth easier and therefore causes fewer infant and mother deaths. An efficient brain also allows us to stop thinking constantly about basic behaviors, such as walking and choosing what to eat, so we can devote mental energy to inventing spears, irrigation systems, and, eventually, airplanes and video games.
30
But conserving mental effort is tricky, because if our brains power down at the wrong moment, we might fail to notice something important, such as a predator hiding in the bushes or a speeding car as we pull onto the street. So our basal ganglia have devised a clever system to determine when to let habits take over. It’s something that happens whenever a chunk of behavior starts or ends.
To see how it works, look closely at the graph of the rat’s neurological habit again. Notice that brain activity spikes at the beginning of the maze, when the rat hears the click before the partition starts moving, and again at the end, when it finds the chocolate.
30
Those spikes are the brain’s way of determining when to cede control to a habit, and which habit to use. From behind a partition, for instance, it’s difficult for a rat to know if it’s inside a familiar maze or an unfamiliar cupboard with a cat lurking outside. To deal with this uncertainty, the brain spends a lot of effort at the beginning of a habit looking for something—a cue—that offers a hint as to which pattern to use. From behind a partition, if a rat hears a click, it knows to use the maze habit. If it hears a meow, it chooses a different pattern. And at the end of the activity, when the reward appears, the brain shakes itself awake and makes sure everything unfolded as expected.
31
This process within our brains is a three-step loop. First, there is a cue, a trigger that tells your brain to go into automatic mode and which habit to use. Then there is the routine, which can be physical or mental or emotional. Finally, there is a reward, which helps your brain figure out if this particular loop is worth remembering for the future:
31
Over time, this loop—cue, routine, reward; cue, routine, reward—becomes more and more automatic. The cue and reward become intertwined until a powerful sense of anticipation and craving emerges. Eventually, whether in a chilly MIT laboratory or your driveway, a habit is born.1.19
315
1.19 a habit is born For more, see A. David Smith and J. Paul Bolam, “The Neural Network of the Basal Ganglia as Revealed by the Study of Synaptic Connections of Identified Neurones,” Trends in Neurosciences 13 (1990): 259–65; John G. McHaffle et al., “Subcortical Loops Through the Basal Ganglia,” Trends in Neurosciences 28 (2005): 401–7; Ann M. Graybiel, “Neurotransmitters and Neuromodulators in the Basal Ganglia,” Trends in Neurosciences 13 (1990): 244–54; J. Yelnik, “Functional Anatomy of the Basal Ganglia,” Movement Disorders 17 (2002): 15–21.
Notes
Amount: 3